Text messaging has become an increasingly popular mode of communication for mobile device users. With text messages, users can communicate in noisy environments such as nightclubs or restaurants, in quiet environments where users do not wish to disturb others, or when users are otherwise unable or reluctant to communicate audibly. In some cases, text messaging also provides a stored record of the conversation between users. These features, as well as numerous others, have made text messaging the primary mode of communication for some mobile device users.
Certain forms of text messaging are made possible by the short message service (SMS) implemented in most mobile communications systems. SMS is designed to send messages of up to 160 characters between mobile devices, and may also be used for various types of broadcast messaging. Unlike voice communication, text messages are not delivered from the sender to the recipient in real-time. Instead, SMS communication is asymmetric, in that it allows the sent text message to be stored within the SMS system until the recipient mobile device can receive the text message. In some mobile communication systems, text messaging is implemented through other messaging protocols, or by using extensions of SMS, such as multimedia messaging service (MMS), enhanced messaging service (EMS), or the like.